I think so, but as I'm still relatively new I'd like opinions of those who know more than I.

The hive in question is a horizontal top bar started from a package in the spring of 2013. I did feed some in late january as I had a warm day and looked and they were down to a couple of bars of honey (then it turned really cold for a couple of weeks).
So why I think they swarmed. There was lots of activity in march and april, in late april I moved the follower board and they were building comb on the last available bar. I added 3 bars. A couple weeks later I check again, still full, I didn't get through the brood but no new comb. The next 2 days (or maybe 3) there were many bees outside the hive, just hanging on the side, it looked like a package worth (3 pounds or so). A day or so later I noticed the hive wasn't as busy. I moved the follower board back and there aren't nearly as many bees in the hive.
So I suspect they swarms one day while I was at work. Any other information I need to provide?

I would suggest that your 3lb package sized cluster of bees on the side of the hive was a swarm. Swarms usually move clear of the hive to cluster but I've certainly had them cling to the hive on occasion. Usually, after the prime swarm has gone the colony still looks quite full and are pretty active and people don't believe their hive could have swarmed, so I would guess that your hive has probably thrown a secondary(cast) swarm or two as well.

Where did you add the extra bars when you put them in and did they build on them? Once swarming prep has started they don't usually build more comb but rather backfill the broodnest with nectar as the queen stops laying. To keep the broodnest expanding you need to put the empty bars in the broodnest rather than at the back of the hive, but there will still come a point where they decide to swarm.

If they have swarmed, your hive will now benefit from a brood break during which time varroa won't be able to breed so that helps control the infestation, so look at it as a positive thing. It may take up to 4 weeks for the new queen to start laying although the norm is 1-2 weeks. Keep an eye on them for pollen forage increase and that will tell you that she has started to lay.

I did add at the end. And it is possible there was more than one swarm. I do view this as a positive (not that I've seen any evidence of varroa, and I take pictures when I inspect to keep the inspection time short while allowing me to examine the comb/bees in detail). One of the reasons I decided to keep bees is that when we first moved here years ago, there were lots of bees of various types in the garden. But in the last few years they haven't been that noticeable. If my bees swarm and it helps get pollinators back in the area then it is a good thing.

ron

Edited to add: I was hoping to hive the swarm in another hive. Oh, well. Such is life.

It has been 3 full weeks since I think they swarmed. As I haven't noticed pollen going in yet, I opened the hive and looked. I did find a queen and saw some bees with pollen in the hive. I didn't see any brood, however I haven't been able to see eggs yet. So I think everything is going well enough. From what I've read and heard, I suspect the queen may have just started laying or is about to.

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot vote in polls in this forum

Quality Top Bar Hives by Andrew Vidler

Conserving wild bees

Research suggests that bumble bee boxes have a very low success rate in actually attracting bees into them. We find that if you create an environment where first of all you can attract mice inside, such as a pile of stones, a drystone wall, paving slabs with intentionally made cavities underneath, this will increase the success rate.

Most bumble bee species need a dry space about the size a football, with a narrow entrance tunnel approximately 2cm in diameter and 20 cm long. Most species nest underground along the base of a linear feature such as a hedge or wall. Sites need to be sheltered and out of direct sunlight.